In case you wondered, the version of Castaway I did that you can download and print (B&W / colour) does feature the aforementioned trademarks, but the logos are all deliberately dirty and scuffed up - I like to pretend I've got plausible deniability. All the same, I've never been shy about referencing brand names in the strip proper - I think the dialogue would be weird and stilted if my characters had to refer to an "iTablet" computer or a refreshing glass of "Kooky Kola". I personally think that Superman, like Brandon Routh or Henry Cavill, is famous enough to be a public figure, and therefore talking about him - assuming I'm not selling my own comics about his adventures - should be kosher.

WW: So I did want to talk about making a few changes.
JH: You have my attention.
WW: I did notice that some of the cards had items with logos on them. The "L" in "HELP" is made from a Coca-Cola sign, the "Alcohol" card is clearly Bacardi, one of the machete cards is a bat'leth...
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JH: A what?
WW: The Klingon sword. Half of one, rather, tied to a stick.
JH: Oh, that. Yeah, I kinda wanted to show that the players are using whatever they can find, stuff salvaged from the shipwreck, et cetera.
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WW: Yeah, I get that, but the Coca-Cola corporation might feel the need to "defend their trademark". I was thinking we'd palette swap, maybe make it "Castaway Cola" or something, just to save the possible hassle.
JH: Yeah, yeah, fair enough. Change the cola brand. You have my blessing.
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WW: Also, one of the floatation devices is a patched-up blowup doll.
JH: She doesn't have any logos on her.
WW: She doesn't have anything on her, that's the problem.